1. Field of the Invention
The present invention relates generally to electronic connector systems and, more specifically, to low-profile connector systems for user-removable electronic modules, such as transceiver modules that interface with a computer.
2. Description of the Related Art
Electrical connectors are used to interconnect circuit cards and other electronic modules or assemblies in computers and other equipment. Various international and industry standards define the type of connectors used to interface computers to external communication devices such as modems, network interfaces, and other transceivers. A well-known type of transceiver developed by an industry consortium and known as a gigabit interface converter (GBIC) or serial optical converter (SOC) provides an interface between a computer and an Ethernet, Fibre Channel or other data communication environment. In co-pending U.S. patent application Ser. No. 09/216,014, a connector system is described that includes an optoelectronic transceiver module of this type that conforms to the Small Form Factor (SFF) standard. The SFF standard specifies a module enclosure 9.8 mm in height by 13.5 mm in width and allowing a minimum of 24 transceivers across a standard rack opening. The connector system includes a connector that is mountable on a circuit card of a computer and into which the transceiver module can be plugged. The connector has a guide rail and cam system that facilitates mechanical mating with the transceiver module. The connector can be mounted on a circuit card behind a bezel of the computer enclosure, with the guide rail extending through an opening in the bezel. The connector further has a connector block with an array of electrical contacts that facilitate electrical mating with complementary contacts of the transceiver module. A user mates the transceiver module with the connector by sliding the module over the end of the guide rail that protrudes through the bezel, and sliding it along the guide rail until the cam fully engages the transceiver module and full mechanical and electrical contact is established. At approximately the point at which the transceiver module becomes fully engaged with the connector, a latch member at the distal end of the guide rail engages a complementary latch member on the module.
Because the guide rail of the above-described connector system protrudes through the opening in the bezel, the latch member at its distal end is subject to being inadvertently bumped or jarred. If the force of such an impact is severe enough, it could damage the latch or guide rail or damage the integrity of the soldered electrical connections between the guide rail and the circuit board upon which it is mounted.
It would be desirable to minimize the likelihood of the above-described damage occurring. The present invention addresses this problem and others in the manner described below.
The present invention relates to an electrical connector system having two connectors in which one of the connectors is included in a module mateable with the other connector in a pluggable manner. The other connector is mountable on a circuit board and includes a body and two or more electrical contacts. In accordance with one aspect of the invention, the body of the mountable connector includes an elongated guide rail with a latch member at its distal end that snaps off if it experiences a jarring force to prevent damage. A snap engagement portion on the latch member mates with a mating snap engagement portion on the distal end of the guide rail. If the latch member snaps off, one can reattach it by snapping it back onto the guide rail. In accordance with another aspect of the invention, the guide rail includes an electrical contact at its distal end that is mateable with the bezel of a computer enclosure in which the connector may be mounted. The mountable connector can be mounted on a circuit board in the computer enclosure, with the guide rail extending through an opening in the bezel. The electrical contact between the bezel and the mountable connector can enhance EMI shielding for the signals carried by the connector system.
In an exemplary embodiment of the invention, the body of the mountable connector is definable by three mutually perpendicular axes and includes a connector block at the proximal end of the guide rail, which is elongated in the direction of the first axis. The connector block retains the contacts, which are spaced from one another in the direction of the first axis. The electrical contacts of the mounted connector may be arrayed in two or more rows, each parallel to the second axis and having two or more contacts. The body, including the connector block, has a very low profile, and in certain exemplary embodiments it is preferably less than about 10 mm in height, i.e., the dimension defined by the third axis, to accommodate the Small Form Factor standard and to facilitate surface-mounting the bottom of the body on the circuit board. The body also includes a cam that, in response to a force of the module being moved along the guide rail, redirects the force in a direction having a component along the third axis so as to cause relative motion and resulting electrical contact between the contacts of the module connector and the contacts of the mounted connector. A cam on the connector block has two complementarily inclined ramp sections. When the module, guided by the guide rail, is moved into initial engagement with the cam, the first ramp lifts the module, including the electrical contacts of its connector, above the connector block of the mounted connector. When the module is moved further into engagement with the cam, the second ramp lowers the module connector onto the connector block, with the contacts of the module connector lowering onto and making contact with the contacts of the mounted connector. The camming motion minimizes wiping between the mating contacts. In addition, the contacts of the mounted connector are preferably somewhat resiliently deflectable to promote good electrical contact.
The foregoing, together with other features and advantages of the present invention, will become more apparent when referring to the following specification, claims, and accompanying drawings.